Some loose tracks

If you have some loose track pad bolts, fit some new ones (get the right ones!) and tighten them up, they may well come loose again but you don't stand much chance of tightening old ones, give us the bolt size and we will give you the correct torque as there was more than on size used on the D4.

Is the best place to order this hardware the dealer or elsewhere? If they're just bolt-in then I'll order a dozen or so bolts and then just attack the bad ones. Most of them really are quite tight.

I am told that the dealer sourced bolts are quite cheap and know they are the best use, anything less will fail.

Track bolts have a taller head on them for wear also.

I believe the shoulder is also of the correct length to eliminate slop in the bolt.

Any bolt will "do".
BUT!
To keep them from coming loose, the correct shouldered bolt IS required!
They will move wearing the threads then becoming sloppy and tearing up the holes in the rails.
Hardware from CAT is very good for the price which is better than most Suppliers.
Buy CAT Bolts!

I'm definitely planning on buying the correct bolts from CAT. After looking in my parts manual last night it looks like there are two options depending on what shoes I have. Need to see if I can find the part number and then I'll go by the dealer and order the right hardware. I'll only order enough to do the loose plates and have a few leftover.